V0BtaTrack list is a list of
BtaCandidate objects that combines
Ks, Lambda, and gamma conversions
that are identified as such by the
TrkV0Selector module in the
This page describes the selection of these particles.
for other aspects of
|Invariant mass of the track pair||[pdg-0.007 GeV, pdg+0.007 GeV]||[0, 0.03 GeV]|
|Distance between the V0 vertex and the primary vertex||[0.5 cm, 80 cm]||[1.5 cm, 80 cm]|
|Distance of closest approach of the track pair||< 0.75 cm|
|Vertex probability of the track pair||> 0.02|
|Primary pointing (dot-product of the V0 flight direction with the normalized displacement vector from the primary vertex)||> 0.998|
|Number of DCH hits before the V0 vertex||<= 2|
|Use of detector PID information||n/a||see below|
In addition, the detector-level PID information is used to further discriminate the Lambda and the gamma conversions. This combines the knowledge from the DRC, DCH, and SVT detectors.